Equity implications of rice fortification: a modelling study from Nepal

Abstract

Objective: To model the potential impact and equity impact of fortifying rice on nutritional adequacy of different subpopulations in Nepal.

Design: Using 24-h dietary recall data and a household consumption survey, we estimated: rice intakes; probability of adequacy (PA) of eight micronutrients commonly fortified in rice (vitamin A, niacin (B3), pyridoxine (B6), cobalamin (B12), thiamin (B1), folate (B9), Fe and Zn) plus riboflavin (B2), vitamin C and Ca and mean probability of adequacy (MPA) of these micronutrients. We modelled: no fortification; fortification of purchased rice, averaged across all households and in rice-buying households only. We compared adequacy increases between population subgroups.

Setting: (i) Dhanusha and Mahottari districts of Nepal (24-h recall) and (ii) all agro-ecological zones of Nepal (consumption data).

Participants: (i) Pregnant women (n 128), mothers-in-law and male household heads; (ii) households (n 4360).

Results: Unfortified diets were especially inadequate in vitamins B12, A, B9, Zn and Fe. Fortification of purchased rice in rice-purchasing households increased PA > 0·9 for thiamin, niacin, B6, folate and Zn, but B12 and Fe remained inadequate even after fortification (PA range 0·3-0·9). Pregnant women's increases exceeded men's for thiamin, niacin, B6, folate and MPA; men had larger gains in vitamin A, B12 and Zn. Adequacy improved more in the hills (coefficient 0·08 (95 % CI 0·05, 0·10)) and mountains (coefficient 0·07 (95 % CI 0·01, 0·14)) but less in rural areas (coefficient -0·05 (95 % CI -0·09, -0·01)).

Conclusions: Consumption of purchased fortified rice improves adequacy and gender equity of nutrient intake, especially in non-rice-growing areas.

Keywords: Diets; Equity; Nepal; Nutritional adequacy; Rice fortification.

Fig. 1

Mean intakes of all rice and purchased rice by province, ecological zone, rural/urban, women and children. Using Annual Household Survey 2014–15 data. Percentage of households purchasing rice is provided below each category. , rice from all sources (purchased, grown, received); , purchased rice only (potential for fortification). NFC, Nepal Food Corporation

Fig. 2

Probability of micronutrient adequacy of women and children in Nepal, with and without rice fortification. Using Annual Household Survey 2014–15 data. Current: based on unfortified diets of total population (women n 5443; children n 3346). Fortified (all): based on total population when bought rice is fortified with World Food Programme (WFP) mid-point values (women n 5443; children n 3346). Fortified (buyers): based on intakes of rice-buying households only, when bought rice is fortified with WFP mid-point values (women n 3007; children n 1882). , current; , full sample; , buyers only. MPA, mean probability of adequacy

Fig. 3

Probability of micronutrient adequacy of pregnant women, their mothers-in-law and male household head in Nepal province 2, with and without rice fortification. From Low Birth Weight South Asia Trial data. Current: based on unfortified diets of all respondents (n 128); Fortified (all): based on intakes of all respondents when bought rice is fortified with World Food Programme (WFP) mid-point values (n 128); Fortified (buyers): based on intakes of rice-buying households only, when bought rice is fortified with WFP mid-point values (n 97). , current; , full sample; , buyers only. MPA, mean probability of adequacy

Fig. 4

Comparison of the difference in probability of adequacy (PA) with and without fortification, between pregnant women and male household heads. Values given above the bars for women represent the difference between pregnant women’s and men’s increase in PA after fortification of rice. P values for tests of differences in the increase in PA between pregnant women and men are provided below each nutrient name, where * P < 0·05, ** P < 0·01, *** P < 0·001. , women; , men. MPA, mean probability of adequacy